folder

kind: folder
name: uploads
spec:
  path: tmp/uploads
---
kind: folder
name: cache
spec:
  cache: true

Spec

field
path	a directory relative to the workspace root; created if missing
cache: true	a directory under the workspace’s cache folder, named after the resource

Give one of the two.

Status

{ "path": "/Users/me/umka/tmp/uploads" }

Read it as ${ folder.cache.status.path } wherever a process needs the location:

kind: process
name: api
spec:
  cmd: cargo
  args: [run, -p, api]
  env:
    CACHE_DIR: ${ folder.cache.status.path }